The Most Important Multiplayer Games of All Time

GameSutra has an article detailing what they consider the most important mp games of all time. They have this to say about Quake.

Gamasutra.com Features - The Quantum Leap Awards: The Most Important Multiplayer Games of All Time:

[Quake] itself was certainly groundbreaking, but I single it out as more of a platform than a specific game. Among the many, many, many things that came out of the Quake development/mod community: 1. GameSpy (then QuakeSpy) and other server browsers, now commonplace if not standard for all multiplayer games; 2. Threewave CTF, which directly influenced just about every team based shooter ever made, even if it’s not always obvious; 3. Team Fortress, which more or less created the class-based shooter that games like Battlefield (and now Quake Wars) have run with; 4. And Rocket Arena, the original one-on-one multiplayer experience. The same community would later move on to Half-Life, and in turn create Counter-Strike, the most successful non-MMO multiplayer, non-casual game of all-time.

Jason Bergman, 2K Games

They forgot that Quake also was the technical fore-runner for almost all of the PC games they list. Quake was the first game to include TCP support as well as the first FPS to use 3D instead of sprites for everything. The community not only spawned what they listed, but also QuakeWorld, the TeamFortress community was responsible for not only class-based gameplay, but also the node-capture game style from the Canalzon map.

Maybe I am just bias because I was part of that community, but most of the people and themes of todays multiplayer games are direct participants in the early Quake community.